When she was between 6 and 8 months old, I went into her bedroom one day to find her out of her cot. She was pulling herself up, dancing and laughing. She'd unscrewed the cot bars and popped them out of their holes at the top. If you look behind her head in the picture you can see the loose bars. I just had to get photographic evidence as I couldn't believe it!
We bought a new cot that very day, and by the time she was 18 months she'd destroyed that one too. We then gave up and put her in a bed. I also remember her being in her playpen, climbing on a toy and forward flipping out over the top, and landing on her feet. She should be in a circus.